NH_4Cl-NH_3-H_2O体系浸出氧化锌矿

Leaching zinc oxide ores in the system of NH_4Cl-NH_3-H_2O

介绍了氯化铵 氨配合浸出法直接从氧化锌矿提取锌新工艺 .该工艺采用氯化铵 氨水溶液作浸出剂 ,使之与氧化锌矿反应得锌氨配合离子 ,在浸出的同时将杂质砷、锑、铁、硫酸根和碳酸根除去 .实验结果表明 :时间、液固比对锌浸出率影响显著 ,而温度对锌浸出率影响不大 ;在综合浸出条件下 ,锌浸出率大于 6 8% ,氨溶锌浸出率大于 93.88% (质量分数 ) ;胶体吸附除砷、锑效果明显 ,浸出液中砷、锑质量浓度可降至 0 .2 5mg·L- 1 ,铁质量浓度可降至 0 .15mg·L- 1 以下 ,氯化钙、氯化钡可将碳酸根和硫酸根几乎除尽 ,其他杂质元素含量也极低 .该浸出液净化容易 ,特别适合制电锌或锌粉 .本法具有工艺简单、能耗低、污染小、原料适应性广等优点 .

A new process for leaching zinc directly from zinc oxide ores in the system of NH 4Cl NH 3 H 2O is described in the paper. In the process NH 4Cl NH 3 H 2O was used as leaching agent, then the Zn(NH 3) 2+ i was formed after the solution reacted with zinc oxide ores. At the same time, the impurities of As, Sb, Fe, SO 2- 4 and CO 2- 3 were removed. The results of experiments show that the effects of time and the ratio of liquid to solid on the rate of zinc leaching is obvious while the effect of temperature is not obvious. Under the best conditions, the rate of zinc leaching was more than 68% and that of zinc leaching which could be dissolved in the system was more than 93.88%. Moreover, absorption of As and Sb by a colloid was very good, and the contents of As and Sb in the leaching liquor were no more than 0.25 mg·L -1 , with oxidant, that of Fe was less than 0.15 mg·L -1 , and with BaCl 2 and CaCl 2, all the CO 2- 3 and SO 2- 4 could be removed. In addition, the contents of the other impurities were very few. The purification of leaching liquor will be very easy and fitted to prepare pure zinc and zinc powder. The method has the advantages of simplified process, high recovery rate of zinc, low power consumption, and little pollution, and so on.